Gas turbine engines have oil systems to meet the needs of rotating components of the engines for continuous oil flows for cooling and lubricating those rotating components. An oil system in a gas turbine engine conventionally includes an oil supply system for delivering oil from an oil source such as an oil tank, to various locations within the gas turbine engine, and an oil scavenging system for recovering used oil from the various locations in the engine and discharging the recovered used oil back into the source such as the oil tank. In a conventional scavenging oil system, conventional displacement pumps which are driven by a dedicated gear train, are used as scavenging pumps. Those displacement pumps and the dedicated gear train are relatively oversized and overweighted in the environment of a gas turbine engine, particularly when used for aircraft.
Accordingly, there is a need to provide an improved gas turbine oil scavenging system.